The TimeZone class represents a time zone; it is
used with the Calendar and DateFormat
classes.

As an abstract class, TimeZone cannot be directly
instantiated. Instead, you should call the static
getDefault() method to obtain a TimeZone
object that represents the time zone inherited from the host
operating system. Or, you should call getTimeZone()
(also static), passing the name of the desired zone. You
can obtain a list of the supported time zone names by calling
the static getAvailableIDs() method.

Once you have a TimeZone object, you can call
inDaylightTime() to determine whether, for a given
Date, daylight savings time is in effect for that
time zone. Call getID() to obtain the name of the
time zone, and call getOffset() for a given date to
determine the number of milliseconds to add to GMT to
convert to the time zone.